The present invention relates to a speaker system used in video appliances such as television receivers, and various audio appliances in automobiles, information communications, etc.
A conventional speaker system is described below while referring to a structural sectional view in FIG. 7 and a perspective exploded view in FIG. 8. A speaker box 1 in the conventional speaker system is composed of a front cabinet 2, a back cabinet 3, and a cover 4, and they are mutually fixed by mounting screws 6. A speaker unit 5 is installed in the opening of the front cabinet 2 to be accommodated in the speaker box 1, and an input cord 7 is connected to the speaker unit 5. A first sound guide c and a second sound guide d are formed in the speaker box 1. Arrow a shown in FIG. 7 indicates a front release wave emitted from the front side of the speaker unit 5, and arrow b denotes a rear release wave emitted from the rear side of the speaker unit 5.
In thus constituted conventional speaker system, the operation is described below. First, when an electric signal is applied to the input cord 7, it is transmitted to the speaker unit 5, and is converted into an acoustic signal by the speaker unit 5, and a sound wave is generated. At this time, the sound emitted from the front side of the speaker unit 5 is generated as a positive front release wave a, and the rear release wave b emitted from the rear side of the speaker unit 5 is extracted by sound guides c, d, so that the bass range that cannot be delivered by the speaker unit 5 alone can be reproduced.
In such conventional constitution, however, due to the vibration of the speaker unit 5 itself or the pressure of the rear release wave b emitted from the speaker unit 5, the back cabinet 3 and the cover 4 in the vicinity of the speaker unit 5 vibrate, which affects the bass range characteristic. If a strong impact is applied to the speaker unit, moreover, the speaker unit 5 may fall out of the front cabinet 2 mounting by the screws 6 is insufficient, and also in the recent trend of reduction of weight of the speaker system, since resins materials are widely used in the speaker, the strength of the front cabinet 2 and back cabinet 3 cannot be reinforced structurally, and therefore enhancement of strength is demanded.